Single crystals of CsV\(_3\) Sb\(_5\)  were grown by the self-flux method [1]}, [2]}. Thin flakes of CsV\(_3\) Sb\(_5\)  were prepared by an Al\(_2\) O\(_3\) -assisted exfoliation method [3]}. Al\(_2\) O\(_3\)  thin film with thickness ranging from 60 to 100 nm was deposited by thermally evaporating Al under an oxygen pressure of 10\(^{-2}\)  Pa on the freshly prepared surface of the bulk CsV\(_3\) Sb\(_5\)  single crystal. Then the Al\(_2\) O\(_3\)  film was picked up with a thermal release tape, along with pieces of CsV\(_3\) Sb\(_5\)  thin flakes separated from the bulk. The Al\(_2\) O\(_3\) /CsV\(_3\) Sb\(_5\)  stack was subsequently released onto a piece of polydimethylsiloxane (PDMS) upon heating, with the CsV\(_3\) Sb\(_5\)  side in contact with the PDMS surface. Next the PDMS was stamped onto a substrate and was peeled away, leaving the Al\(_2\) O\(_3\)  film covered with CsV\(_3\) Sb\(_5\)  thin flakes on the substrate. Figure 1(b) displays an optical image of CsV\(_3\) Sb\(_5\)  thin flake on Al\(_2\) O\(_3\)  film supported on a 300 nm SiO\(_2\) /Si substrate. Then the electrodes were fabricated on the CsV\(_3\) Sb\(_5\)  thin flake with direct metal deposition through stencil masks. All the devices were fabricated in an argon atmosphere with O\(_2\)  and H\(_2\) O content kept below 0.5 parts per million to avoid sample degradation.
